Separator for juxtaposed sheets

ABSTRACT

A pair of feed rollers is arranged transversely to the path of travel of a pair of juxtaposed sheets. One feed roller has spaced surface portions in peripheral surface contact with the other feed roller. One surface portion is momentarily axially shifted toward the other by actuator means to create a buckle in the leading edge of one sheet. A separator element intercepts the buckled leading edge of the one sheet to separate the pair while in transit.

D United States Patent 1111 3, 14,095 [72] Inventors Christian A. Beck [56] R f r n e Cited g jf h N 81k M h fc UNITED STATES PATENTS [21] A I No 5 5 609,968 8/1898 Larson 271/21 [22] ig g 27 1970 2,731,263 l/1956 Bariletal... 271/64X [45] Paemed Oct 3 3,301,550 1/1967 Reinecke 271/51 [73] Assignee Pitney-Bowes, Inc. Primary Examiner.loseph Wegbreit Stamford, Conn. Assistant ExaminerBruce H. Stoner, Jr.

[5 4] SEPARATOR F OR J UXTAPOSED SHEETS Attorneys-William D. Soltow, Jr., Albert W. Scribner and Martin D. Wittstein ABSTRACT: A pair of feed rollers is arranged transversely to the path of travel of a pair of juxtaposed sheets. One feed roller has spaced surface portions in peripheral surface contact with the other feed roller. One surface portion is momentarily axially shifted toward the other by actuator means to create a buckle in the leading edge of one sheet. A separator element intercepts the buckled leading edge of the one sheet to separate the pair while in transit.

PATENTEUUBT 19 197i sum 1 or 2 3,614,095

PIC-ll FIG. 3

INVENTORS CHRISTIAN A. BECK FRANZ. A. TOMASCH 1 M; p mm ATTORNEY SHEET 2 BF 2' null-"nun" I. I

l-lll INVENTORS CHRISTIAN A. BECK BY FRANZ A.TOMASC,H

ATTORNEY BACKGROUND AND OBJECTS OF THE INVENTION Occasions arise where it is desirable to separate paper sheets which are juxtaposed in overall surface contact with each other. The prior art is replete with apparatus for separating the top or bottom sheet from a stationary sheet stack pursuant to feeding sheets seratim through processing apparatus, such as photocopy machines. However, it is another matter to separate juxtaposed sheets while they are in transit. Heretofore, separation of juxtaposed sheets moving along a common feed path has been typically accomplished by pre-establishing a misregistration between the sheets as they enter the common feedpath. Typically, the sheets are arranged such that the entire leading edge of one sheet slightly overlaps the leading edge of the other. In this situation, it is a relatively simple matter to design a mechanism to grasp or intercept only the overlapped leading edge in achieving sheet separation without interruption of sheet movement.

In certain applications, it is not desirable to have misregistration between sheets as they are jointly fed through processing stations. For example, if the juxtaposed sheets comprise an original and a copy sheet and the image borne by the original is to be reproduced on the copy in a copying process, complete registration of the sheets is desirable. That is, it is unattractive to have, for example, the copy sheet with larger or smaller dimensions than the original sheet in order to achieve an overlapping edge. Obviously, this would result in a shifting of the location of the reproduced image on the copy sheet as compared to the location of the original image on the original sheet. This can be overcome by making the copy sheet larger than the original and, after image reproduction, trimming the copy sheet. However, this requires additional time and/or apparatus.

It is accordingly an object of the present invention to provide improved apparatus for separating juxtaposed sheets while in transit.

An additional object is to provide apparatus of the above character wherein sheet separation is achieved efiiciently and wrinkling or creasing of the individual sheets is avoided.

A further object of the invention is to provide apparatus of the above character which is capable of achieving sheet separation of sheets in substantially exact registration.

A further object is to provide apparatus of the above character which can operate on one portion of a pair of juxtaposed sheets to initiate sheet separation without disturbing processing operations being performed simultaneously on other portions of the pair of sheets.

Another object of the invention is to provide apparatus of the above character which is compact and simple in design, inexpensive to manufacture, and extremely reliable in operatron.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

SUMMARY OF THE INVENTION Generally in accordance with the invention, there is provided a pair of opposed feed rollers arranged generally transversely to the path of travel of a pair of sheets which are juxtaposed in overall surface contact. One of the feed rollers is formed having an interruption in its peripheral surface intermediate its ends so as to provide axially spaced apart peripheral surface portions; each portion being in peripheral surface contact with the other feed roller. The feed rollers are counterrotated such that the juxtaposed sheets are translated upon entry into the nip therebetween.

Actuator means are provided to engage the feed roller having the spaced surface portions so as to axially shift one of its peripheral surface portions toward the other, thus reducing the spacing therebetween. This axial shifting of the one surface portion occurs in timed relation to the passage of a juxtaposed pair of sheets between the feed rollers such that a buckle is created in the leading edge of one sheet. A separator element is positioned beyond the feed rollers to intercept the buckled leading edge of the one sheet such that the sheets being fed by the feed rollers pass on opposite sides of the separator.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying DETAILED DESCRIPTION The apparatus of the invention as seen in the various figures of the drawings includes a pair of elongated feed rollers, generally indicated at 10 and 12, arranged transversely to the path of travel of a pair 14 of juxtaposed paper sheets 14a and 14b. As seen in FIG. 1, the sheets 14a and !14b have their leading and lateral edges in substantial registration as they jointly move in the direction of arrow 15 toward the nip of feed rollers 10 and 12.

Feed roller 10 consists of an elongate shaft 16 which carries an elongate cylinder 18 formed of a suitable material such as rubber. The ends of the shaft 16 are joumaled in bushings 20 mounted by side frame members 22, as seen in FIG. 6.

Feed roller 12 consists of an elongate shaft 24 on which is fitted a rubber cylinder 26, typically of the same material as cylinder 18 but approximately one-half of the length thereof, as best seen in FIG. 6. Cylinder 26 is positioned on the left half of shaft 24 with its left end substantially aligned with the left end of cylinder 18. A sleeve 28 is slidingly received on shaft 24 adjacent the right end of the shaft as viewed in FIG. 6. The left-hand end of this sleeve has opposed axially extending slots 280 formed therein which receive the ends of a pin 30 accommodated in a bore 30a extending diametrically through shaft 24. By virtue of this construction, sleeve 28 is permitted a limited degree of axial movement on shaft 24 while being rotated thereby through the connection afiorded by pin 30.

Sleeve 28 carries an outer sleeve 32 typically formed of the same material as cylinders 18 and 16. The peripheral surface of sleeve 32 lies on substantially the same diameter as the peripheral surface of cylinder 26 such that both are in peripheral surface contact with the cylinder 18 of feed roller 10. Sleeve 32 moves with sleeve 28 as the latter is rotated and shifted axially on shaft 24.

The ends of the shaft 24 are joumaled in bushings 20 mounted in side frames 22. In practice, bushings 20 would be split into upper and lower halves and spring biased toward each other so as to insure peripheral surface contact between cylinder 18 and cylinder 26 and sleeve 32. By the same token, the feed rollers 10 and 12 readily separate to accommodate the entry of the sheet pair 14 therebetween. The peripheral surface of cylinder 18 then engages the upper surface of upper sheet 14a and the peripheral surfaces of cylinder 26 and sleeve 32 then engage the lower surface of lower sheet ll4b.

As seen in FIG. 6, the right end of shaft 24 extends beyond side frame 22 and mounts a sprocket 34 which is driven to impart rotation thereto. Feed roller 10 may be separately driven in synchronism with feed roller 12, however, in the disclosed embodiment of FIG. 6, feed roller 10 is counterrotated by feed roller 12 due to the peripheral surface contact therebetween.

Still referring to FIG. 6, the assembly of sleeves 28 and 32 slidingly mounted on shaft 24 of feed roller 12 is biased to the right by coil spring 36 working against a stop in the form of a washer 38 lodged in an annular recess formed in shaft 24. The right-hand end portion of sleeve 28 is formed into a radially extending flange 28b which abuts the end of outer sleeve 32. lntennediate sleeve 28 and side frame 22, a cam member 40 is slidingly mounted on shaft 24. Cam member 40 has a generally conical peripheral surface configuration so as to provide a cam surface 40a which is acted upon by actuator arm 42a of a crank 42, as seen in FIG. 5. The crank 42 is pivotally mounted to side frame 22 by a pin 44 and has its upper end connected to a reciprocating link 45 by a pin 46. The other end of link 45 carries a cam follower 47 which rides in a cam track 48 recessed into the flat surface of a wheel 50 rotating on a shaft 52. A spring 54 hooked at one end to a collar 56 carried on shaft 52 and at its other end to a tab 45a depending from link 45 biases the link to the left as seen in FIG. such that the cam follower 47 always bears against the outer cam surface 484 of cam track 48. Pins 58 carried by side frame 22 and received in elongate apertures 45b formed in link 45 maintain horizontal orientation of the link while permitting reciprocal movement thereof.

From the description thus far, it is seen that as the wheel 50 turns in the counterclockwise direction as indicated by arrow 51, the cam follower 47 drops into the valley 48b formed in cam surface 48a which otherwise lies on a common diameter. Spring 54 thus forces link 45 to the left as seen in FIG. 5 with the result that crank 42 is pivoted in the counterclockwise direction. Actuating arm 42a bears against the cam surface 40a of cam element 40 forcing it to the left as seen in FIG. 6. This pushes the assembly of sleeves 28 and 32 to the left against the force of spring 36. As cam follower 47 rides out of the valley 48b in cam surface 480 the link 45 is shifted to the right, permitting the sleeve assembly to be returned to its position shown in FIG. 6 by spring 36.

For an understanding of the manner in which the apparatus of the invention achieves separation of the sheet pair 14, reference is had to FIGS. 1 through 4. First, however, there is one remaining component of the apparatus still to be described. This component is a separator plate 60 as shown in FIGS. 1 through 4 stationed beyond the feed rollers and 12 to confront the leading edge of the sheet pair as it exits from the feed rollers.

As seen in FIG. 1, the sheet pair 14 is fed toward the feed rollers 10 and 12 as indicated by arrow 15, while the feed rollers l0 and 12 are counterrotated in the directions indicated by arrow 19. Thus, as the sheet pair enters the nip of feed rollers l0 and 12, sheets 14a and 14b are pressed together and jointly fed toward separator plate 60. It is seen that the peripheral surface contact of the cylinder 18 on feed roller 10 is continuous with the upper surface of sheet 140 along the entire width of the sheet. On the other hand, the peripheral contact of feed roller 12 with the under surface of sheet 14b is interrupted by the gap between cylinder 26 and sleeve 32.

Now, if the rotation of wheel 50 (FIG. 5) is coordinated with the feeding of the sheet pair 14 such that the cam follower 47 falls into the valley 48b in cam surface 48a at substantially the time the physical relationship of the sheet pair to the feed rollers is that depicted at FIG. 2, i.e., with the leading edge of the sheet pair 14 just exiting from the nip of the feed rollers, the resulting movement of the sleeve 32 of feed roller 12 toward cylinder 26 will produce a downward buckle 17 (FIG. 3) in the leading edge of the lower sheet 1412. It is seen that neither sheet can buckle upwardly in response to the inward movement of sleeve 32 due to the uninterrupted peripheral surface of feed roller 10. The leading edge of the upper sheet 140 will not buckle downward since the frictional engagement between it and the peripheral surface of the cylinder 18 is greater than the frictional engagement between the interface surfaces of sheets 14a and 14b. By the same token, the momentary inward movement of the sleeve 32 is effective to create buckle 17 in sheet 14b since the frictional engagement of its surface with sleeve 32 is greater than the frictional engagement between the overlying mutually contacting surfaces of the sheets. Thus, because of the interruption in the peripheral surface of feed roller 12 and the movement of the left leading comer of sheet 14b toward the opposite corner can only result in the downward buckle 17. However, it is understood that the positions of the feed rollers may be reversed such that the buckle 17 is formed in the leading edge of upper sheet 14a.

As seen in FIG. 3, the separator plate 60 is formed having a pointed projection 60a positioned to intercept the buckle 17 and enter into the separation formed between sheets 14a and 14b as the sheet pair is advanced toward the separator plate by the feed rollers. As seen in FIG. 4, as the sheet pair continues to be advanced by the feed rollers, the initial separation (buckle 17) is expanded into a complete separation along the entire width of the sheet pair such that sheet 14a passes over the separator element 60 while the lower sheet 14b passes beneath it.

It has been found that the axial shifting of the sleeve 32 need be only to a limited extent in order to create a buckle 17 suffcient to effect complete separation of the sheet pair 14. By way of specific example, to separate sheets having a lateral dimension of 8'): inches, it has been found that momentarily shifting sleeve 32 inwardly one thirty-second to one-sixteenth of an inch causes a sufficient buckle to initiate sheet separation. Moreover, the sleeve 32 need only remain in its shifted position momentarily, that is, only long enough for the projection 60a to intercept the buckle 17. Once the projection 60a intervenes between the sheets 14a and 14b, the sleeve 32 may return to its normal position shown in FIG. 6. This is seen from the configuration of the cam surface 48a wherein the return from the valley portion 48b is achieved with only a small increment of rotation of the wheel 50.

It is appreciated that the relative lateral dimensions of the cylinder 26 and sleeve 32 may vary from that shown in the drawings. However, it is desirable to limit the lateral portion of the leading edge of sheet 14b in which buckle 17 can occur as this serves to amplify the amplitude of the buckle and to insure its alignment with projection 60a of separator plate 60. Moreover, it is preferable to make the axial length of sleeve 32 short relative to the axial length of cylinder 26, as then the frictional forces at the interface of the sheets to be overcome in creating the buckle 17 are relatively small.

While the apparatus of the invention is conducive to a number of applications, one specific application which readily demonstrates the advantages of the invention is shown in FIG. 5. It is assumed that one of the sheets of the pair 14 is an original document sheet while the other is a copy sheet on which is to be reproduced the image borne by the original. In the illustrated application of the invention shown in FIG. 5, the copy paper may be of the type having a photoconductive zinc oxide coating thereon. The sheet pair is fed through a corona charger, generally indicated at 62 in FIG. 5, to place a uniform electrostatic charge on the surface of the zinc oxide coating on the copy sheet. The sheet pair 14 then is fed by feed roller pairs 64 and 66 through an illuminating station, generally indicated at 70, where the copy sheet is selectively discharged so as to produce a latent electrostatic image corresponding to the image borne by the original sheet.

The sheet pair 14 is then guided by a guide plate 72 to the nip of feed rollers 10 and 12. The sheets are separated, passing over and under separator element 60, with the lower sheet 14b being supported on guide plate 74. The original sheet would be returned to the operator while the copy sheet would be passed through a developer station (not shown) where the image is rendered visible and fixed, and then deposited in a receptacle (not shown) accessible to the operator.

It is seen that the apparatus of the invention can operate on the leading edge of the sheet pair in order to initiate separation without disturbing the various operations being performed on the terminal portion of the sheet pair. It is appreciated that it would be in an intolerable situation if the sheet separating operation produced movement in the portions of the sheets then passing through the illuminating station 70. This would invariably result in poor image reproduction. While in the illustrated application, the feed rollers 66 at the exit of the illuminating station 70 would prevent the buckle 17 in sheet 14b from extending into the illuminating station, it is nevertheless a virtue of the present invention that the buckle may be made small enough so that it will not extend for any significant distance along the length of sheet 14b. Thus, the buckle created to initiate separation of the leading edge of the sheets making up the sheet pair need not prejudice various operations being performed on the terminal, juxtaposed portions of the sheets.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are effciently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described our invention what we claim as new and desire to secured by Letters Patent is:

1. In a photocopy machine having an imaging station through which an original and a copy sheet are jointly translated in juxtaposed relation along a common feed path, sheet handling apparatus comprising, in combination:

A. means disposed in the feed path beyond the imaging station and having 1. a first surface portion engaging one of the sheets, and

2. second and third spaced surface portions arranged transversely to the direction of sheet travel and each engaging the other sheet;

B. actuator means operating to decrease the spacing between said second and third surface portions so as to create a buckle in the leading edge of the other sheet while the sheets continue in motion; and

C. a separator element positioned in the feed path and having means for intercepting the buckled edge portion of the other sheet, whereby the sheets are separated and pass on opposite sides of said separator element.

. The apparatus defined in claim 1, wherein said first surface portion is carried by a first feed roller,

and

2. said second and third surface portions are carried by a second feed roller said second and third surface portions being in separate peripheral surface contact with said first surface portion in the absence of the sheets,

3. said feed rollers being rotated to feed the sheets upon introduction therebetween.

3. Apparatus for handling a pair of juxtaposed sheets being translated in a first direction along a common feed path, said apparatus comprising, in combination:

A. means disposed in the sheet pair feed path and including 1. a first surface portion engaging one of the sheets, 2. second and third spaced surface portions engaging the other of the sheets;

B. actuator means operating to produce a relative movement between said first, second and third surface portions for producing a relative movement between the sheets in a second direction, thereby resulting in a partial separation therebetween; and

C. a separator element positioned in the feed path and having means for intercepting the separated portion of one of the sheets as the sheet pair continues to move in the first direction, whereby the sheets pass on opposite sides of said separator element. 4. Apparatus for handling a pair of juxtaposed sheets being 5 translated in unison along a common feed path, said apparatus comprising, in combination:

A. first and second opposed feed rollers arranged transversely to the path of travel of the sheet pair, said feed rollers counterrotating to feed the sheet pair upon entry into the nip therebetween; t means forming an interruption in the peripheral surface of said first feed roller intennediate the ends thereof to thus provide spaced first and second peripheral surface portions thereof, each in surface contact with the peripheral surface of said second feed roller in the absence of the sheet pair therebetween;

C. actuator means operating to decrease the spacing between said first and second peripheral surface portions as the leading edges of the sheet pair pass between said feed rollers to thereby create a buckle in the leading edge of one sheet; and

D. a separator element positioned beyond said feed rollers to intercept the buckled leading edge of the one sheet whereby the sheets being fed by said feed rollers are separated and pass on opposite sides of said separator element.

5. The apparatus defined in claim 4, wherein said first feed rollers includes 1. a shaft,

2. a cylinder carried on said shaft to provide said first peripheral surface portion, and

3. sleeve slidingly mounted on said shaft to provide said second peripheral surface portion.

6. The apparatus defined in claim 5, wherein the separation between said cylinder and said sleeve is less than one-half the length of the leading edge of the one sheet.

7. The apparatus defined in claim 6 wherein the axial length of said cylinder is substantially greater than the axial length of said sleeve.

8. The apparatus defined in claim 5 wherein said actuator means includes 1. a cam member slidingly mounted on said shaft against the end of said sleeve remote from said cylinder, said member having a conical cam surface, and

2. an actuating element movable into engagement with said cam surface to force said cam member and said sleeve from their normal positions toward said cylinder.

9. The apparatus defined in claim 8 wherein said actuator means further includes a spring mounted on said shaft inter 50 mediate said sleeve and cylinder, said spring acting on said sleeve to return it and said cam member to their normal positions as said actuating element moves away from said cam surface.

10. The apparatus defined in claim 6 wherein said separator element is formed having a projection positioned in alignment with the buckle in the one sheet.

11. The apparatus defined in claim 6, wherein said first feed roller further includes means carried by said shaft for limiting the movement of said sleeve toward said cylinder.

12. The apparatus defined in claim 1!, wherein said cylinder and said sleeve are constrained to rotate with said shaft. 

1. In a photocopy machine having an imaging station through which an original and a copy sheet are jointly translated in juxtaposed relation along a common feed path, sheet handling apparatus comprising, in combination: A. means disposed in the feed path beyond the imaging station and having
 1. a first surface portion engaging one of the sheets, and
 2. second and third spaced surface portions arranged transversely to the direction of sheet travel and each engaging the other sheet; B. actuator means operating to decrease the spacing between said second and third surface portions so as to create a buckle in the leading edge of the other sheet while the sheets continue in motion; and C. a separator element positioned in the feed path and having means for intercepting the buckled edge portion of the other sheet, whereby the sheets are separated and pass on opposite sides of said separator element.
 2. second and third spaced surface portions arranged transversely to the direction of sheet travel and each engaging the other sheet; B. actuator means operating to decrease the spacing between said second and third surface portions so as to create a buckle in the leading edge of the other sheet while the sheets continue in motion; and C. a separator element positioned in the feed path and having means for intercepting the buckled edge portion of the other sheet, whereby the sheets are separated and pass on opposite sides of said separator element.
 2. The apparatus defined in claim 1, wherein
 2. said second and third surface portions are carried by a second feed roller said second and third surface portions being in separate peripheral surface contact with said first surface portion in the absence of the sheets,
 2. a cylinder carried on said shaft to provide said first peripheral surface portion, and
 2. an actuating element movable into engagement with said cam surface to force said cam member and said sleeve from their normal positions toward said cylinder.
 2. second and third spaced surface portions engaging the other of the sheets; B. actuator means operating to produce a relative movement between said first, second and third surface portions for producing a relative movement between the sheets in a second direction, thereby resulting in a partial separation therebetween; and C. a separator element positioned in the feed path and having means for intercepting the separated portion of one of the sheets as the sheet pair continues to move in the first direction, whereby the sheets pass on opposite sides of said separator element.
 3. sleeve slidingly mounted on said shaft to provide said second peripheral surface portion.
 3. said feed rollers being rotated to feed the sheets upon introduction therebetween.
 3. Apparatus for handling a pair of juxtaposed sheets being translated in a first direction along a common feed path, said apparatus comprising, in combination: A. means disposed in the sheet pair feed path and including
 4. Apparatus for handling a pair of juxtaposed sheets being translated in unison along a common feed path, said apparatus comprising, in combination: A. first and second opposed feed rollers arranged transversely to the path of travel of the sheet pair, said feed rollers counterrotating to feed the sheet pair upon entry into the nip therebetween; B. means forming an interruption in the peripheral surface of said first feed roller intermediate the ends thereof to thus provide spaced first and second peripheral surface portions thereof, each in surface contact with the peripheral surface of said second feed roller in the absence of the sheet pair therebetween; C. actuator means operating to decrease the spacing between said first and second peripheral surface portions as the leading edges of the sheet pair pass between said feed rollers to thereby create a buckle in the leading edge of one sheet; and D. a separator element positioned beyond said feed rollers to intercept the buckled leading edge of the one sheet whereby the sheets being fed by said feed rollers are separated and pass on opposite sides of said separator element.
 5. The apparatus defined in claim 4, wherein said first feed rollers includes
 6. The apparatus defined in claim 5, wherein the separation between said cylinder and said sleeve is less than one-half the length of the leading edge of the one sheet.
 7. The apparatus defined in claim 6 wherein the axial length of said cylinder is substantially greater than the axial length of said sleeve.
 8. The apparatus defined in claim 5 wherein said actuator means includes
 9. The apparatus defined in claim 8 wherein said actuator means further includes a spring mounted on said shaft intermediate saiD sleeve and cylinder, said spring acting on said sleeve to return it and said cam member to their normal positions as said actuating element moves away from said cam surface.
 10. The apparatus defined in claim 6 wherein said separator element is formed having a projection positioned in alignment with the buckle in the one sheet.
 11. The apparatus defined in claim 6, wherein said first feed roller further includes means carried by said shaft for limiting the movement of said sleeve toward said cylinder.
 12. The apparatus defined in claim 11, wherein said cylinder and said sleeve are constrained to rotate with said shaft. 